Chapter 1 - Section 1.6 - Subtraction of Real Numbers - Exercise Set - Page 70: 1

$ a.\quad$the additive inverse of 12 is $-12$ $b.\quad 5-12=5+(-12) $

a. the additive inverse of 12 is $-12.$ b. To subtract $b$ from $a,\ \mathrm{a}\mathrm{d}\mathrm{d}$ the opposite, or additive inverse, of $b$ to $a.$ $a-b=a+(-b)$ $5-12=5+(-12)$ $=-7$